US2395189A - Synchronizer - Google Patents

Description

Feb. 19, 1946. R. LAPSLEY ET AL 2,395,189

SYNGHRONIZER Original Filed Feb. 7, 1940 2 Sheets-Sheet 1 IN VEN TORS Robert La $12 1 By Donald 5. ence flitorlzey 1946- R. LAPSLEY ET AL 2,395,139

SYNCHRONIZER Original Filed Feb. 7, 1940 2 Sheets-Sheet 2 V D 5 51 2.2 4 1 v %wf UNITED STATES PATENT OFFICE SYNCHRONIZER Robert Lapsley and Donald S. Dence, Berrien Spring, Micln, assignors to Clark Equipment Company, Buchanan, Micln, a corporation of Michigan Original application February 7, 1940, Serial No. 317,658. Divided and this application July 12,

1944, Serial No. 544,585

4 Claims. (Cl. 192-107) This invention relates to synchronizers, and more particularly is directed to synchronizers for transmissions and the like involving friction cone rings and the method of and means for insure a tight press fit, to provide for interlocking the ring and the sleeve against relative circumferential movement. This can be readily accomplished during the forming operation,

manufacturing and assembling the same on syn- 5 since the outer-circumferential edge of the flat chronizer sleeves. This application is a division blank may be notched during the stamping operof our copending applications Serial No. 317,658, ation and such notches form interlocking keys now Patent No. 2,319,740, issued May 18, 1943 when the lip is bent thereover. and Serial No. 382,952 filed March 12, 1941, and is A still further feature of the present invention directed particularly to the synchronizer sleeve resides in the heat treating of the synchronizer and the means for assembling and securing the sleeve in such manner that a relatively soft friction ring in said sleeve. ductile lip is left after the machining operations Heretofore, such rings have been formed from which produce the tapered recess, whereby this tubular stock which has been forged or otherlip can be readily bent over to lock the friction wise shaped, and then the rings are pressed ring in position. onto the receiving surfaces of the synchronizer Thus, the synchronizer assembly may be desleeve. This has resulted in their cost being signed so that the friction rings are interlocked. relatively high, and has also required relatively both axially and circumferentially, by relatively accurate fits in order to insure proper seating simple means insuring proper operation of the of the ring in the receiving recess of the sleeve. synchronizer in a transmission construction. I

The present invention contemplates reducing Other objects and advantages of the present the cost of manufacture of the rings by forming invention will appear more fully from the followthem from metal blanks or strips which are cut ing detailed description which, taken in conto arcuate form and then rolled into proper form junction with the accompanying drawings, will for insertion into the sleeve recesses. Such disclose to those skilled in the art the particublanks or strips may be formed of a suitable ring lar construction and operation of a preferred material such as bronze sheets, or may be formed form of the present invention. from a bi-metalllc or clad metal in which a In the drawings: layer of bearing material is bonded to a steel Figure l is a sectional view through a portion base surface. When the blanks are stamped out of a transmission illustrating a synchronizer of the sheet they are in arcuate form with the embodying the present invention; 7 outer are being equivalent to the circumference Figure 2 is a detailed view of a portion of the of the larger end of the ring .and the inner arc end of a synchronizer sleeve showing the manbeing equivalent to the circumference of the ner in which the friction ring recess is formed; smaller end. The blanks may be provided with Figure 3 is a pa P p e i owin oil grooves all milled simultaneously by a multhe friction ring in position; tipie milling operation, while the blank is in a Figure 4 is an end elevational view of the synfiat form whereby when the blank is rolled into chronizer sleeve with the friction ring assemconical form the grooves are slightly dove-tailed bled therein; in shape providing sharp cutting edges for the til Figure 5 is a detailed sectional view showing a lubricant film. modified manner of interlocking the friction ring Another feature of the present invention is and sleeve; to simplify the blank construction so that it may Figure 6 illustrates the blank from which the be quickly and economically formed and placed friction ring is for ed; and in position. The means for securing the blank Figure '7 is a Sect o a V w through One im in position is particularly advantageous since of material which may be used in making the it insures the ring from moving axially with re= friction ring. spect to the seat on the synchronizer sleeve, 7 Referring now in detail to Figure 1, a more or which axial lock may be secured either by bendless conventional type of transmission structure ing inwardly a small axially projecting lip on is shown in which the transmission case b has the outer end of the sleeve recess, or by b ending journalled therein the shaft 6 by means of bearthe inner edge of the blank into the blocking ing i, the shaft 6 having an enlarged end '11 prorecesses formed in the sleeve. vided with the external gear teeth 8 adapted to It may also be desirable under certain eonmesh with the gear 9 keyed to the countershait ditions, such as where the angularity will not M W- A second geariZ on the countershaft it is adapted to have meshing engagement with a gear l3 rotatably journalled as by the needle rollers l4 upon a shouldered portion ii of a main transmission shaft 18 having its end 11 piloted in the recessed end of the shaft 6 by means of the bearings l8. Intermediate the end I1 and shoulder ii of the shaft ii the shaft is provided with a splined portion 20 upon which is mounted the clutch sleeve 22, this sleeve having external clutch teeth 23 and 24 at opposite ends thereof and being provided intermediate its ends with radially extending finger portions 25 adapted to extend thr ugh suitable openings 25 formed in an enclosing synchronizer sleeve 21.

Each 'of the gears 8 and 13 are provided with internal clutch teeth 30 and 32, respectively, adapted to be selectively engaged by the clutch sleeve 22 upon axial shifting movement thereof along the shaft portion 20.

Disposed radially outwardly of the clutch teeth 30 and 3 2, the gears 8 and II are provided with frusto-conical surfaces 33 and 34, respectively, adapted to be engaged by friction rings 85 and 36, respectively, carried by the synchronizer sleeve 27.

The main elements of the synchronizer constructlon,-insofar as its blocking action and cooperative relation between the sleeve and clutch portions is concerned, is disclosed in detail in the copending application of Leo A. Bixby and Robert Lapsiey, Serial No. 298,391, filed October '7, 1939, now Patent No. 2,256,308 issued September 16, 1941. The present invention more particularly is concerned with the manner in which the rings 35 and 38 are formed and the means by which they are secured within the frustoconical recesses in the ends of the sleeve 21.

Considering these features of the invention more in detail, the sleeve 21 is preferably subjected to a carburizing treatment in which it is packed in carbon and heated in a conventional manner to provide a depth of case substantially as shown by the layer 4. of case material shown in Figure 2. This material is removed at the ends of the sleeve along the dotted line indicated at 42, providing the frusto-conical recessed surface 43 and the axially projecting lip 44. The surface 43 is of the same angled inclination as the surfaces 33 and 34 of the gears 8 and I3, but is radially enlarged'so as to provide for the introduction of the friction ring carried by the synchronizer sleeve and adapted, upon initial movement of the clutch yoke 3| shown in Figure 1, to bear against the respective surfaces 33 and 34 to bring the selected gear and clutch to substantially synchronous relationship before the final clutching movement, whereby the clutch sleeve 22 is moved into meshing engagement with the associated gear.

The friction ring 50 adapted to be received on the surface 43 is preferably formed from flat plate, such as bronze sheets or the like, or it may be formed from clad material such as shown in Figure '1 in which the base 52 is formed of mild steel, for, example, and has a layer of bearing material 53 bonded thereto to form an integral union of the two materials and provide a sheet having a substantially uniform thickness of bearing material bonded thereon. It is aphaving an outer are equivalent to the circumference of the larger end of the cone ring and having inner arcs equivalent to the inner circumference of the cone ring. Such blanks are sub- Jected while in the fiat form to a multiple milling operation which provides a plurality of parallel grooves 55 in the face portion thereof, which grooves are preferably rectangular in section so that when the blank 5' has been rolled into conical form the defining edges of the groove, as shown clearly in Figure 3, present sharp cutting edges for cutting the oil film present on the surfaces 33 and 34 of the gears. The stamping is accurately cut to length so that when rolled into conical form the two ends abut in tight engagement, providing a ring when once pressed into the tapered recess 48. This ring is pressed along the tapered seat until a tight press fit is obtained, the dimensions being controlled so that the ring at no time moves inwardly into engagement with the radial shoulder 45. When the ring has thus been pressed into position, the outer end of the axial lip 44 is spun radially inwardly over the outer end or large diameter end of the ring, as shown at 60 in Figure 1, thereby locking the ring against outward axial displacement.

Depending upon the angularity desired on the friction surfaces, it may be desired in some cases to provide a circumferential interlocking between the ring and the synchronizer sleeve as well as the axial lock. For such purposes, the blank II shown in Figure 6 may be stamped with spaced notches 62 formed in the large diameter edge thereof, which notches thereby are disposed at the larger end of the from-conical ring when pressed into position. The swaging or pressing operation which bends over the lip 44 into engagement around the outer end of the ring I. may then also provide for indentation of the lip into the notches I! as shown at 63 in Figure 3, thereby providing a circumferential interlock preventing relative circumferential displacement between the ring and the synchronizer sleeve. Such a construction is shown in end elevation with portions broken away in Figure 4, and it will be at once apparent that with such a construction, both axial and circumferential movement of the ring relative to the synchronlzer sleeve is prevented.

An optional method of locking the ring II in position on the synchronizer sleeve 21 is illustrated in Figure 5, in which it will be noted that under-cut grooves ll are providde in the internal surface of the synchronizer sleeve adjacent the finger openings 26. The inner or small end of the ring 50 in this form of the invention is bent into such grooves which extend circumferentially between the openings 26, and at the openings the inner end of the ring is bent inwardly as shown at 12 to provide the circumferential interlock, the axial interlock being provided by the radially in,- wardly bent portions 13 intermediate the openings 28. Thus, in this form of the invention, the same type of axial and circumferential interlock is produced, but the-inner end-of the ring is employed for this P p in place of the outer end of the ring. This eliminates the necessity for the machining operations to cut oi! the excess materials along the dotted line 42 of Figure parent that either type of ring may be employed 0 2 as the synchronizer sleeve may be carburized in any of the assemblies shown in Figures 1-6 inclusive.

Sheets of either of these types are then subjected to a stamping operation in'which arcuate and no further machining except for the surface 43 need be provided.

If desired, the modification shown in Figure 5 can be varied, for the sake of economy, by elimblanks 5! are stamped therefrom, these blanks II inating the undercut groove 10 and merely bending the lip or edge 12 radially outwardly over the defining ends of openings 26 to hold the ring 50 against axial outward displacement. In such are the equivalent of the forged ringspreviously employed, and have the advantage of greatly reduced cost of manufactureas well as facilitating the formation of the oil grooves therein.

In addition, it will be apparent that the novel type of means for locking the rings in position relative to the synchronizer sleeves is of great advantage in cases where either axial locking is required or where both axial and circumferential locking of the ring to the sleeve is necessary.'

We are aware that various changes may be made in certain details of the present invention without, however, departing from the underlying principles thereof, and we therefore do not inmovement relative to said seat with portions of said end being pressed into said openings to lock said ring against circumferentia1 movement.

2. In combination, a synchronizer sleeve having a frusto-conical recess in one end thereof, a frusto-conical friction ring adapted to be pressed into said recess, said ring overlying the axial inner end of said recess and having the overlying portion bent radially outwardly axially to lock said ring against axial and circumferential movement relative to said sleeve.

3. A synchronizer sleeve having an annular recess in the end thereof, an annular friction ring seated in said recess and having a frusto-conical friction surface, said sleeve having formed therein at the inner end of said ring circumferentially spaced openings, the inner edgeof said ring having portions thereof radially outwardly displaced into said openings to lock said ring and sleeve against relative axial and circumferential movement.

4. A synchronizer sleeve having an annular recess in the end thereof, a friction ring seated tend to be limited except as defined by the scope in saidrecess and having a frusto-conical inner friction surface, said sleeve having circumferentially spaced openings formed adjacent the inner edge of said ring and having an internal annular groove at the inner end of said recess, said ring having the inner edge thereof forced radially outwardly into said groove with portions thereof being pressed into said openings whereby said ring is locked against relative axial or circumferential movement with respect to said sleeve.

ROBERT LAPSLEY. DONALD S. DENCE.

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